1. Technical Field
The present invention relates to a method of forming an insulating film for use in a semiconductor device, and a method of manufacturing a semiconductor device.
2. Related Art
A high dielectric constant film typified by oxidation tantalum (referred to as Ta2O5) is favorable as a material for a next generation gate oxide film in a dynamic random access memory (referred to as DRAM) or the like. In addition, it can be given that a metal insulator metal (referred to as MIM) decoupling capacitor is incorporated in a semiconductor chip as one of solutions for various problems that would arise with improvement of complementary metal oxide semiconductor (referred to as CMOS) devices. This can effectively eliminate a transient voltage for supplying the chip. In a 90 nm process and subsequent processes, effectiveness of an on-chip capacitor is growing from the viewpoint of effective frequency and instantaneous demand power.
The higher dielectric constant makes a capacitance insulating film for use in the MIM decoupling capacitor more useful. As a material with high dielectric constant, Ta2O5, ZrO2, HfO2, and the like can be used. Examples of typical manufacturing processes include a chemical vapor deposition (referred to as CVD) process, an atomic layer deposition (referred to as ALD) process, an O2 plasma oxidation process, a dry O2 thermal oxidation process, and the like. Above all processes, the dry O2 thermal oxidation process has advantages in that its technique is simple and its device is comparatively inexpensive.
A known method of forming Ta2O5 is disclosed in Japanese Unexamined Patent Publication No. H08-293494, for example. The same document discloses that TaN0.8 formed by a reactive direct current (referred to as DC) sputtering process or the CVD process is subjected to dry O2 oxidation at a temperature range of 300 to 600 degrees centigrade to form Ta2O5.
In addition to Japanese Unexamined Patent Publication No. H08-293494, Japanese Unexamined Patent Publication No. H05-136342 can be given as an example of a conventional art document related to the present invention.